A 49 year-old North-East man is being questioned by police hunting the infamous Ripper hoaxer - Wearside Jack.

John Humble, who lives on Sunderland's Ford Estate, was arrested on Tuesday and was still being questioned by detectives late last night.

Earlier in the day, the former security guard's home in Flodden Road was sealed off and forensic experts carried out an inch-by-inch search of the two-bedroomed council house.

After his arrest - on suspicion of attempting to pervert the course of justice - Mr Humble was taken to West Yorkshire to be interviewed.

Detectives have spent 27 years investigating the sending of a tape and letters, which fooled police into believing the Yorkshire Ripper was from the Castletown area of Sunderland.

It is thought the arrest came after police found the hoax letters, which were believed to have been lost, and unearthed new DNA evidence.

The hoax letters and tapes taunted officers and diverted resources from the investigation - as Peter Sutcliffe continued to kill three more women, including 20-year-old Middlesbrough student Jacqueline Hill.

A spokesman for West Yorkshire Police would only confirm that police were searching a house in Flodden Road, in the Ford area of Sunderland, in connection with the inquiry.

Neighbours said Mr Humble - known locally as John The Bag because he is seen most days with a carrier full of alcohol - was separated from his wife, and now lives with his brother.

David Carroll, who said he was Mr Humble's nephew, added: "I am shocked by all of this as I know that is not his voice on that tape."

Mr Carroll, 43, from Sunderland, said his uncle had been born on the Hylton Lane Estate, near the scene of Tuesday arrest, and had no links with Castletown.

Sutcliffe, from Bradford, now 59, was jailed for life in 1981 for the murder of 13 women. He is held in Broadmoor secure hospital.

In the late 1970s and 1980 his killings brought terror across the North and placed huge pressure on the murder team, led by Assistant Chief Constable George Oldfield.

But the inquiry - the biggest manhunt in Britain - was led down a blind alley by the three letters and a tape sent to the investigation team by a man dubbed Wearside Jack because of his strong Sunderland accent.

The first letter was sent to Mr Oldfield in March 1978, the second to the Daily Mirror three days later, and the third to Mr Oldfield in March 1979.

In June 1979, Mr Oldfield played the two-minute message to a spellbound nation.

It began: "I'm Jack. I see you are still having no luck catching me. I have the greatest respect for you, George, but Lord, you are no nearer catching me now than four years ago when I started. I reckon your boys are lettin' you down, George. They can't be much good, can they?"

The detective said he was sure it was the Ripper's voice and a huge police effort was directed to the Sunderland area.

Linguistics expert Stanley Ellis concluded the voice on the tape came from a man from the Castletown area.

Suspicion hung over the community for a year-and-a-half until Sutcliffe was caught in Sheffield early in 1981.

Sutcliffe had been questioned a number of times but was eliminated from the inquiry, partly because of his West Yorkshire accent.

The biggest controversy over the Wearside Jack tape and letters was whether Mr Oldfield's decision to concentrate so much effort on it meant Sutcliffe was able to murder three more women while the police were distracted.

At Sutcliffe's Old Bailey trial, Mr Justice Boreham said: "The scent was falsified by a cynical, almost inhuman hoaxer.

"I express the hope that one day he may be exposed."

Lord Mackenzie, a former chief superintendent with Durham Police, last night said diverting resources away from West Yorkshire to the North-East had cost lives, and the culprit should face a manslaughter charge.